Chemical contaminants found at Superfund sites and in their leachates may play a significant role in the causation of human disease and in the deterioration of ecosystem health. Thus, such disease and ecological degradation is preventable to the extent that such factors can be identified and either removed from the environment or counteracted. Recognition of this possibility requires intensified efforts to identify the causal factors, to determine those conditions which modulate their bioavailabilities, to elucidate their mechanisms of action and to formulate appropriate measures for blocking or reversing their effects. The purpose of this Program is to provide training to prepare scientists for active and productive careers in environmental toxicology with interdisciplinary emphases on environmental engineering, bioremediation, ecology, and biomedical research. The objective is to prepare the trainees to plan, conduct, and interpret toxicological studies which are appropriate to specific scientific issues regarding the fate and effects of Superfund contaminants on human and wildlife populations. The scope of this program is broad. For example, trainees will be provided with backgrounds enabling them to study genetic and epigenetic factors which impact variation in susceptibilities to environmentally-induced disease in humans and in fish by metals and aromatic hydrocarbons and to understand those factors which influence bioavailabilities of these contaminants in ecosystems. The program provides for two predoctoral (Ph.D.) And four internship positions.